Abstract: The validity of the recently developed Sport Orientation Questionnaire (SOQ), a multidimensional measure of sport achievement orientation, was investigated with both high school and university students. Specifically, we examined the correlations of SOQ scores with other measures of competitiveness and general achievement orientation and we compared the relative abilities of SOQ scores and other achievement measures to discriminate participants and nonparticipants in competitive sports, noncompetitive sports, and nonsport activi-ties. The findings obtained with both high school and university students provided convergent and divergent evidence for the validity of the SOQ. SOQ scores were highly correlated with other competitiveness measures, moderately correlated with general achievement measures, and uncorrelated with competitive anxiety and social desirability. Competitiveness scores were the strongest discriminators between competitive sport participants and nonparticipants, but SOQ scores were weaker discriminators for noncompetitive achievement choices. The findings confirm the value of a multidimensional, sport-specific achievement measure and provide good evidence for the validity of the Sport Orientation Questionnaire.